Semiconductor device and method of manufacturing the same

ABSTRACT

A semiconductor device and a method of manufacturing a semiconductor device may be provided. The semiconductor device may include a source line formed over a substrate. The semiconductor device may include a channel pattern including a connection part disposed over the source line, and pillar parts protruding from the connection part in a first direction. The semiconductor device may include a well structure protruding from the connection part in the first direction and spaced apart from the source line. The semiconductor device may include a source contact structure protruding from the source line in the first direction and passing through the connection part. The semiconductor device may include a gate stack disposed between the source contact structure and the well structure and enclosing the pillar parts over the connection part.

CROSS-REFERENCE TO RELATED APPLICATION

The present application claims priority under 35 U.S.C. § 119(a) toKorean patent application number 10-2017-0115979 filed on Sep. 11, 2017,in the Korean Intellectual Property Office, the entire disclosure ofwhich is incorporated herein by reference.

BACKGROUND 1. Technical Field

Various embodiments of the present disclosure may generally relate to asemiconductor device and a method of manufacturing the same, and moreparticularly, to a three-dimensional semiconductor memory device and amethod of manufacturing the same.

2. Related Art

A semiconductor device includes a plurality of memory cell transistorscapable of storing data. The memory cell transistors may be coupled inseries between select transistors, thus forming a memory string. Athree-dimensional semiconductor device may be embodied by stacking gatesof the memory cell transistors and the select transistors on asubstrate.

SUMMARY

In an embodiment of the present disclosure, a semiconductor device maybe provided. The semiconductor device may include a source line formedover a substrate. The semiconductor device may include a channel patternincluding a connection part disposed over the source line, and pillarparts protruding from the connection part in a first direction. Thesemiconductor device may include a well structure protruding from theconnection part in the first direction and spaced apart from the sourceline. The semiconductor device may include a source contact structureprotruding from the source line in the first direction and passingthrough the connection part. The semiconductor device may include a gatestack disposed between the source contact structure and the wellstructure and enclosing the pillar parts over the connection part.

In an embodiment of the present disclosure, a semiconductor device maybe provided. The semiconductor device may include gate stacks disposedover a source line. The semiconductor device may include a sourcecontact structure disposed between the gate stacks and protruding towardthe source line further than the gate stacks so that the source contactstructure is coupled to the source line. The semiconductor device mayinclude insulating spacers disposed between the gate stacks and thesource contact structure. The semiconductor device may includehorizontal extension parts protruding from a sidewall of a lower end ofthe source contact structure that is adjacent to the source line andoverlapping the insulating spacers.

In an embodiment of the present disclosure, a method of manufacturing asemiconductor device may be provided. The method may include forming astack enclosing a channel layer and disposed over a source line, thechannel layer including a connection part disposed over the source lineand pillar parts extending from the connection part in a firstdirection, the stack enclosing the pillar parts of the channel layerover the connection part of the channel layer. The method may includeforming a first opening and a second opening passing through the stackto divide the stack into gate stacks and expose the connection part. Themethod may include forming a well doping layer extending along a surfaceof the first opening and a surface of the second opening. The method mayinclude removing a portion of the well doping layer from the secondopening to expose the second opening. The method may include forming asource trench extending from the second opening to expose the sourceline. The method may include forming a source contact layer which fillsthe source trench and the second opening.

In an embodiment of the present disclosure, a method of manufacturing asemiconductor device may be provided. The method may include forming asource line. The method may include forming a channel layer including, aconnection part extending parallel to the source line, and pillar partsprotruding from the connection part in a first direction. The method mayinclude forming gate stacks enclosing the pillar parts and disposed overthe connection part. The method may include forming insulating spacerson sidewalls of the gate stacks. The method may include forming a sourcecontact structure including horizontal extension parts protruding tooverlap the insulating spacers, the source contact structure beingdisposed between the gate stacks and passing through the connection partso that the source contact structure is coupled to the source line.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 shows a schematic circuit diagram of a semiconductor device inaccordance with an embodiment of the present disclosure.

FIGS. 2A and 2B show plan views illustrating a semiconductor device inaccordance with an embodiment of the present disclosure.

FIGS. 3A and 3B show sectional views illustrating a semiconductor devicein accordance with an embodiment of the present disclosure.

FIG. 4 shows a sectional view illustrating a semiconductor device inaccordance with an embodiment of the present disclosure.

FIG. 5 shows an enlarged view of region C shown in FIG. 3A, 3B, or 4.

FIGS. 6A to 6L shows sectional views illustrating a method ofmanufacturing a semiconductor device in accordance with an embodiment ofthe present disclosure.

FIG. 7 shows a sectional view illustrating a method of manufacturing asemiconductor device in accordance with an embodiment of the presentdisclosure.

FIGS. 8A and 8B are sectional views illustrating a method ofmanufacturing a semiconductor device in accordance with an embodiment ofthe present disclosure.

FIG. 9 shows a block diagram illustrating the configuration of a memorysystem in accordance with an embodiment of the present disclosure.

FIG. 10 shows a block diagram illustrating the configuration of acomputing system in accordance with an embodiment of the presentdisclosure.

DETAILED DESCRIPTION

Example embodiments will now be described more fully hereinafter withreference to the accompanying drawings; however, they may be embodied indifferent forms and should not be construed as limited to theembodiments set forth herein. Rather, these embodiments are provided sothat this disclosure aids in a description of the present teachings, andconveys a description to those skilled in the art.

In the drawing figures, dimensions may be exaggerated for clarity ofillustration. It will be understood that when an element is referred toas being “between” two elements, it can be the only element between thetwo elements, or one or more intervening elements may also be present.

Hereinafter, embodiments will be described with reference to theaccompanying drawings. Embodiments are described herein with referenceto cross-sectional illustrations that are schematic illustrations ofembodiments (and intermediate structures). As such, variations from theshapes of the illustrations as a result, for example, of manufacturingtechniques and/or tolerances, are to be expected. Thus, embodimentsshould not be construed as limited to the particular shapes of regionsillustrated herein but may include deviations in shapes that result, forexample, from manufacturing. In the drawings, lengths and sizes oflayers and regions may be exaggerated for clarity. Like referencenumerals in the drawings denote like elements.

Terms such as ‘first’ and ‘second’ may be used to describe variouscomponents, but they should not limit the various components. Thoseterms are only used for the purpose of differentiating a component fromother components. For example, a first component may be referred to as asecond component, and a second component may be referred to as a firstcomponent and so forth without departing from the spirit and scope ofthe present disclosure. Furthermore, ‘and/or’ may include any one of ora combination of the components mentioned.

Furthermore, a singular form may include a plural from as long as it isnot specifically mentioned in a sentence. Furthermore,“include/comprise” or “including/comprising” used in the specificationrepresents that one or more components, steps, operations, and elementsexist or are added.

Furthermore, unless defined otherwise, all the terms used in thisspecification including technical and scientific terms have the samemeanings as would be generally understood by those skilled in therelated art. The terms defined in generally used dictionaries should beconstrued as having the same meanings as would be construed in thecontext of the related art, and unless clearly defined otherwise in thisspecification, should not be construed as having idealistic or overlyformal meanings.

It is also noted that in this specification, “connected/coupled” refersto one component not only directly connecting another component but alsoindirectly connecting to another component through an intermediatecomponent. On the other hand, “directly connected/directly coupled”refers to one component directly connecting to another component withoutan intermediate component.

Embodiments of the present disclosure provide a three-dimensionalsemiconductor device having improved operational reliability, and amethod of manufacturing the same.

FIG. 1 shows a schematic circuit diagram of a semiconductor device inaccordance with an embodiment of the present disclosure.

Referring to FIG. 1, the semiconductor device in accordance with anembodiment may include a plurality of memory strings SR coupled betweenbit lines BL and a source line CSL.

The memory strings SR may be arranged in a zigzag manner to improve adegree of integration of the semiconductor device. The arrangement ofthe memory strings SR may be defined by an arrangement of pillar partsof a channel pattern. The arrangement of the pillar parts of the channelpattern will be described later herein with reference to FIG. 2A.

Each of the memory strings SR may include a source select transistorSSTa or SSTb, a plurality of memory cell transistors MC1 to MCn (n is anatural number of 2 or more), and a drain select transistor DSTa or DSTbthat are coupled in series to each other by a pillar part of the channelpattern. Each of the memory strings SR may include a single drain selecttransistor DSTa or two or more drain select transistors DSTa and DSTbcoupled in series to each other. Each of the memory strings SR mayinclude a single source select transistor SSTa or two or more sourceselect transistors SSTa and SSTb coupled in series to each other.

The memory strings SR may be coupled to gate stacks GST1 and GST2.Although FIG. 1 illustrates a first gate stack GST1 and a second gatestack GST2, the number of gate stacks is not limited thereto.

Each of the gate stacks GST1 and GST2 may include a source select lineSSLa or SSLb, word lines WL1 to WLn, and a drain select line DSLa orDSLb. Each of the gate stacks GST1 and GST2 may include a single sourceselect line SSLa disposed under the word lines WL1 to WLn, or two ormore source select lines SSLa and SSLb spaced apart from each other anddisposed under the word lines WL1 to WLn. Each of the gate stacks GST1and GST2 may include a single drain select line DSLa disposed over theword lines WL1 to WLn, or two or more drain select lines DSLa and DSLbspaced apart from each other and disposed over the word lines WL1 toWLn.

The word lines WL1 to WLn are coupled to gates of the memory celltransistors MC1 to MCn. The source select lines SSLa and SSLb arecoupled to gates of the source select transistors SSTa and SSTb. Thedrain select lines DSLa and DSLb are coupled to gates of the drainselect transistors DSTa and DSTb. The drain select lines DSLa and DSLbcontrol electrical connection between the memory strings SR and the bitlines BL. The source select lines SSLa and SSLb control an electricalconnection between the memory strings SR and the source line CSL.

The source line CSL may be coupled to the memory strings SR via a sourcecontact structure SCL. The memory strings SR may be coupled to a wellpick-up line WPL via a well structure WE. The well structure WE may bedisposed on one side of each of the gate stacks GST1 and GST2, and asource contact structure SCL may be disposed on the other side thereof.In other words, each of the gate stacks GST1 and GST2 may be disposedbetween the well structure WE and the source contact structure SCLdisposed adjacent to the well structure WE.

The source line CSL is coupled to a discharge transistor CST. Thedischarge transistor CST may include a gate terminal, a source terminal,and a drain terminal. The discharge transistor CST may be disposedbetween the source line CSL and a substrate SUB as shown in FIG. 3B or4. One of the source terminal and the drain terminal of the dischargetransistor CST is coupled to the source line CSL, and the other iscoupled to the ground. The discharge transistor CST may couple thesource line CSL to the ground in response to a signal applied to thegate terminal. In other words, the discharge transistor CST maydetermine whether to discharge the voltage of the source line CSL.

According to the above-described circuit, each of the memory strings SRin accordance with an embodiment may include a first terminal coupled tothe well structure WE, a second terminal coupled to the source line CSL,a third terminal coupled to each of the word lines WL1 to WLn, and afourth terminal coupled to the bit line BL. Particularly, in anembodiment of the present disclosure, because the first terminal coupledto the well structure WE is separated from the second terminal coupledto the source line CSL, an operation of controlling an erase operationthrough the well structure WE, and an operation of controlling a readoperation or a program operation through the source line CSL may beindividually performed. Thereby, the operational reliability of thesemiconductor device in accordance with an embodiment of the presentdisclosure may be enhanced.

FIGS. 2A and 2B are plan views illustrating a semiconductor device thatforms the circuit shown in FIG. 1. FIGS. 2A and 2B illustrate only oneside of the gate stacks.

FIG. 2A shows a plan view illustrating the structure disposed belowupper lines.

Referring to FIG. 2A, each of the gate stacks GST1 and GST2 is disposedbetween the source contact structure SCL and the corresponding wellstructure WE that are adjacent to each other. Each of the gate stacksGST1 and GST2 encloses the corresponding pillar parts PP of the channelpattern CH. In other words, the pillar parts PP of the channel patternCH pass through the gate stacks GST1 and GST2. Hereinafter, a directionin which the pillar parts PP extend is defined as a first direction I.

The gate stacks GST1 and GST2 may include a stepwise contact area. Thegate stacks GST1 and GST2 may form memory blocks. The gate stacks GST1and GST2 may extend in a second direction II and a third direction III.The second direction II and the third direction III intersect with eachother. The second direction II and third direction III perpendicularlyintersect with the first direction I. The source contact structure SCLand the well structure WE extend parallel to each other in the seconddirection II. One of the gate stacks GST1 and GST2 may be disposedbetween the source contact structure SCL and the well structure WE thatare adjacent to each other in the third direction III. Source contactstructures SCL and well structures WE may be alternately arranged in thethird direction III. The well structure WE faces the source contactstructure SCL with the gate stack GST1 or GST2 interposed between thewell structure WE and the source contact structure SCL. Although FIG. 2Aillustrates a case where the source contact structure SCL and the wellstructure WE extend in a line shape in the second direction II, thepresent disclosure is not limited thereto. For example, each of thesource contact structure SCL and the well structure WE may be dividedinto a plurality of plug patterns spaced apart from each other in thesecond direction II.

Insulating spacers IS may be formed along sidewalls of the gate stacksGST1 and GST2. The insulating spacers IS may be disposed between thewell structure WE and the gate stacks GST1 and GST2 and between thesource contact structure SCL and the gate stacks GST1 and GST2 so thatthe gate stacks GST may be insulated from the well structure WE and thesource contact structure SCL. The source contact structure SCL iscoupled to the source line CSL disposed below the gate stacks GST1 andGST2. The connection relationship between the source line CSL and thesource contact structure SCL is illustrated in FIGS. 3A or 4.

The memory strings SR are defined along the pillar parts PP of thechannel pattern CH. The pillar parts PP may be arranged in a zigzagmanner. Each of the memory strings SR further includes a multilayermemory layer ML. The multilayer memory layer ML may extend along anouter surface of the channel pattern CH. In one example, the multilayermemory layer ML may extend from a space between the channel patterns CHand the gate stack GST1 and GST2 into a space between the channelpatterns CH and the source line CSL. The channel pattern CH furtherincludes a connection part coupled to the pillar parts PP. Theconnection part is disposed between the source line and the gate stacksGST1 and GST2. The structure of the connection part of the channelpattern CH is illustrated in FIGS. 3A to 4.

The gate stacks GST1 and GST2 may be supported by supports IP disposedunder the gate stacks GST1 and GST2. The supports IP may be disposed notto overlap the pillar parts PP, or only parts of the pillar parts PP mayoverlap the support parts IP.

Each of the pillar parts PP of the channel pattern CH may be formed toenclose a corresponding capping pattern CAP. The capping pattern CAP maybe electrically coupled to the channel pattern CH to transmit a signalfrom the bit line to the channel pattern CH.

FIG. 2B shows a plan view illustrating a layout of the upper lines.

Referring to FIG. 2B, the upper lines may include the bit lines BLcoupled to the pillar parts PP of the channel pattern CH, and the wellpick-up line WPL coupled to the well structure WE. The upper lines mayfurther include a source dummy line SDL coupled to the source contactstructure SCL. The upper lines BL, WPL, and SDL, are disposed over thegate stacks GST1 and GST2.

The bit lines BL may be electrically coupled to the pillar parts PPthrough bit line contact plugs BCT. Each of the bit line contact plugsBCT may come into contact with at least one of the corresponding pillarpart PP and the associated capping pattern CAP shown in FIG. 2A andextend toward the corresponding bit line BL. Although not shown, the bitlines BL may be coupled to a peripheral circuit to transmit a drivingvoltage to the pillar parts PP.

The well pick-up line WPL may be electrically coupled to the wellstructure WE through a well contact plug WCT. The well pick-up line WPLmay be coupled to the peripheral circuit to supply a well voltage to thewell structure WE.

The source dummy line SDL may be electrically coupled to the sourcecontact structure SCL through the dummy contact plug DCT. The sourcedummy line SDL may be formed of a low-resistance metal layer so that theresistance of the source line that is coupled to the source contactstructure SCL may be reduced. The source dummy line SDL may be formed oflow-resistance metal such as tungsten or aluminum. The source dummy lineSDL may be formed of the same material as the bit lines BL and disposedon the same layer as the bit lines BL. The source dummy line SDL may beomitted as needed. If the source dummy line SDL is omitted, a margin inthe arrangement of the upper lines may be increased.

The gate stacks GST1 and GST2 may be coupled to the gate contact plugsGCT. The gate contact plugs GCT may be respectively coupled to gateelectrodes that are exposed through stepwise structures of the gatestacks GST1 and GST2, and may extend in the first direction I.

FIGS. 3A and 3B show sectional views illustrating a semiconductor devicein accordance with an embodiment of the present disclosure. FIG. 4 showsa sectional view illustrating a semiconductor device in accordance withan embodiment of the present disclosure. In more detail, FIG. 3A shows asectional view taken along line A-A′ shown in FIG. 2B. FIG. 3B shows asectional view taken along line B-B′ shown in FIG. 2B. FIG. 4 shows asectional view taken along line A-A′ of FIG. 2B to illustrate amodification of the well structure.

Referring to FIGS. 3A to 4, the source line CSL may be disposed over asubstrate SUB including a peripheral circuit PERI. The peripheralcircuit PERI includes driving transistors CST and PTR configured tocontrol the operation of the memory string SR. The driving transistorsCST and PTR may include a discharge transistor CST configured to couplethe source line CSL to the ground.

The driving transistors CST and PTR of the peripheral circuit PERI maybe arranged to have various structures and be coupled to the memorystring SR through contact plugs and routing lines having variouslayouts.

The peripheral circuit PERI, and the contact plugs and the routing linesthat are coupled to the peripheral circuit PERI may be covered with afirst lower insulating layer LIL1. The first lower insulating layer LIL1may be formed of multiple insulating layers.

A second lower insulating layer LIL2 penetrated by a lower sourcecontact plug LSCT may be provided on the first lower insulating layerLIL1. The lower source contact plug LSCT may include a metal layer M1.The lower source contact plug LSCT may further include a barrier metallayer BM1. The barrier metal layer BM1 of the lower source contact plugLSCT may be disposed between the metal layer M1 and the second lowerinsulating layer LIL2 to prevent the metal layer M1 and the second lowerinsulating layer LIL2 from coming into direct contact with each other.

The lower source contact plug LSCT may be coupled to any one of a sourceterminal and a drain terminal of the discharge transistor CST. The lowersource contact plug LSCT may be coupled to the discharge transistor CSTvia the contact plugs and the routing lines that are formed in the firstlower insulating layer LIL1.

The source line CSL is coupled to the lower source contact plug LSCT andformed on the second lower insulating layer LIL2. The source line CSLmay include a first conductivity type dopant. The first conductivitytype dopant may be an n-type dopant. In detail, the source line CSL mayinclude a source doping semiconductor layer SDP including a firstconductivity type dopant. The source doping semiconductor layer SDP maybe an n-type doped silicon layer. The source line CSL may furtherinclude a metal layer M2. The metal layer M2 of the source line CSL maybe disposed under the source doping semiconductor layer SDP, and mayreduce the resistance of the source doping semiconductor layer SDP. Thesource line CSL may further include a barrier metal layer BM2 disposedbetween the metal layer M2 and the second lower insulating layer LIL2.The barrier metal layer BM2 of the source line CSL may prevent the metallayer M2 and the second lower insulating layer LIL2 from coming intodirect contact with each other.

The source line CSL may be penetrated by the supports IP configured tosupport the gate stacks GST1 and GST2. The supports IP may protrudefurther than the source line CSL in the first direction that is theupward direction. The gate stacks GST1 and GST2 may be disposed over thesource line CSL at positions spaced apart from the source line CSL.

The channel pattern CH extends along the space between the source lineCSL and the gate stacks GST1 and GST2, and protrudes in the firstdirection I to pass through the gate stacks GST1 and GST2. In moredetail, the channel pattern CH may include a connection part LP andpillar parts PP. The connection part LP and the pillar parts PP form theintegrated channel pattern CH without having an interface therebetween.The channel pattern CH including the connection part LP may be disposedover the source line CSL.

The connection part LP is disposed on the source line CSL. The pillarparts PP protrude from the connection part LP in the first direction andpass through the gate stacks GST1 and GST2. The pillar parts PP areparts enclosed by the gate stacks GST1 and GST2, and extend along innersurfaces of holes passing through the gate stacks GST1 and GST2. Theconnection part LP is disposed in the space between the source line CSLand the gate stacks GST1 and GST2, and encloses the supports IP. Theconnection part LP couples the pillar parts PP with each other. Theconnection part LP extends along the bottom of each of the gate stacksGST1 and GST2, the sidewalls of the supports IP, and an upper surface ofthe source line CSL.

The channel pattern CH may be enclosed by the multilayer memory layerML. The multilayer memory layer ML may extend along the outer surface ofthe channel pattern CH. In other words, the multilayer memory layer MLextends along surfaces of the pillar parts PP and the connection partLP. The channel pattern CH may be formed to enclose a gap-fillinsulating pattern FI.

The gap-fill insulating pattern FI is enclosed by the pillar parts PP.The space between the source line CSL and the gate stack GST1 or theGST2 is filled with the gap-fill insulating pattern FI. The gap-fillinsulating pattern FI extends in the first direction I to pass throughthe gate stack GST1 or GST2. Parts of the gap-fill insulating pattern FIthat pass through the gate stack GST1 or GST2 are enclosed by the pillarparts PP. A part of the gap-fill insulating pattern FI that is disposedbetween the source line CSL and the gate stack GST1 or GST2 is enclosedby the connection part LP. The source contact structure SCL may bedisposed between the gap-fill insulating pattern FI that passes throughthe first gate stack GST1, and the gap-fill insulating pattern FI thatpasses through the second gate stack GST2.

The gap-fill pattern FI may have a height less than the pillar parts PP.In this case, a capping pattern CAP may be disposed on an upper end ofeach gap-fill insulating pattern FI. Each capping pattern CAP may beenclosed by an upper end of the associated pillar part PP. Each of thecapping patterns CAP may be formed of a semiconductor layer including afirst conductivity type dopant. For example, each of the cappingpatterns CAP may be formed of a silicon layer doped with an n-typedopant. Each of the capping patterns CAP may be used as a drainjunction.

The capping patterns CAP may protrude further in the first direction Ithan the gate stacks GST1 and GST2. The capping patterns CAP may becovered with a first upper insulating layer UIL1.

Each of the supports IP may have a sidewall enclosed by the connectionpart LP. The multilayer memory layer ML extends between the connectionpart LP and the supports IP.

Each of the pillar parts PP of the channel pattern CH may be coupled toa corresponding one of the bit lines BL. The bit lines BL may bedisposed on a second upper insulating layer UIL2. The second upperinsulating layer UIL2 is formed on the first upper insulating layerUIL1. The bit lines BL may be coupled to the pillar parts PP of thechannel pattern CH via bit line contact plugs BCT passing through thefirst and second upper insulating layers UIL1 and UIL2. The bit linecontact plugs BCT may be coupled to the capping patterns CAP.

The connection part LP of the channel pattern CH may be coupled to thewell structure WE. The well structure WE protrudes from the connectionpart LP in the first direction I and is spaced apart from the sourceline CSL. At least a portion of the well structure WE that comes intocontact with the connection part LP of the channel pattern CH mayinclude a second conductivity type dopant different from the firstconductivity type dopant. The second conductivity type dopant may be ap-type dopant. The p-type dopant in the well structure WE may be asource of holes to be supplied to the channel pattern CH during an eraseoperation.

For example, the well structure WE may include a well doping layer WDPincluding an ohmic contact area OC, and a metal layer M3 disposed on thewell doping layer WDP. The well doping layer WDP may come into contactwith the connection part LP of the channel pattern CH and extend in thefirst direction I, and the well doping layer WDP may be formed lowerthan the gate stack GST1 or GST2. The well doping layer WDP may be asemiconductor layer doped with a second conductivity type dopant. Forexample, the well doping layer WDP may be a p-type doped silicon layer.A second conductivity type dopant may be distributed at a firstconcentration in the well doping layer WDP under the ohmic contact areaOC. The ohmic contact area OC may include a second conductivity typedopant at a second concentration higher than the first concentration forthe purpose of providing ohmic contact.

As shown in FIG. 3A, the well doping layer WDP may be formed such that aspace between the insulating spacers IS is completely filled therewith.Alternatively, as shown in FIG. 4, the well doping layer WDP may beformed to have a U-shaped cross-sectional structure rather than having ashape that completely fills the space between the insulating spacers IS.In this case, the well structure WE may further include an undopedsemiconductor layer UDP enclosed by the well doping layer WDP disposedbetween the insulating spacers IS. The undoped semiconductor layer UDPmay remain after a process of forming the source contact layer SC of thesource contact structure SCL has been performed. Thus, in an embodiment,the source contact layer SC may be formed of the undoped semiconductorlayer UDP.

Referring to FIGS. 3A to 4, the connection part LP of the channelpattern CH may be coupled to the source line CSL through the sourcecontact structure SCL. The source contact structure SCL may come intocontact with the source line CSL and protrude from the source line CSLin the first direction to pass through the connection part LP. Thesource contact structure SCL may extend into the source line CSL. Thesource contact structure SCL may include a source contact layer SC and ametal layer M3. The source contact layer SC extends from the source lineCSL in the first direction and may be formed lower than the gate stackGST1 or GST2. The source contact layer SC may include a lower end Pwhich comes into contact with the source line CSL and the connectionpart LP of the channel pattern CH. The source contact layer SC may beformed of an undoped semiconductor layer. In more detail, the sourcecontact layer SC may be formed of an undoped silicon layer. The lowerend P of the source contact layer SC that comes into contact with thesource line CSL may include a first conductivity type dopant diffusedfrom the source line CSL. In accordance with an embodiment of thepresent disclosure provided to simplify a manufacturing process, asecond conductivity type dopant different from the first conductivitytype dopant may be distributed in an upper end of the source contactlayer SC that faces the bit line BL, whereby a dummy contact area DC maybe defined. The dummy contact area DC may be formed during a process offorming the ohmic contact area OC.

The source contact layer SC may include an undoped area. The undopedarea may remain between the source line CSL and the dummy contact areaDC. The undoped area may prevent formation of a PN diode structurecaused by a connection between the dummy contact area DC and the sourceline CSL. The undoped area may block the supply of holes from the dummycontact area DC. Particularly, the undoped area may remain between thelower end P of the source contact layer SC in which the firstconductivity type dopant diffused from the source line CSL isdistributed, and the dummy contact area DC in which the secondconductivity type dopant is distributed.

The metal layers M3 of the well structure WE and the source contactstructure SCL may be formed through the same process. The metal layer M3of the well structure WE comes into contact with the ohmic contact areaOC and extends in the first direction. The metal layer M3 of the sourcecontact structure SCL comes into contact with the dummy contact area DCand extends in the first direction. Each of the well structure WE andthe source contact structure SCL may further include a barrier metallayer BM3 to prevent the metal layer M3 and the insulating spacers ISfrom coming into direct contact with each other.

According to the above-mentioned structure, the source contact structureSCL extends toward the source line CSL further than the well structureWE. In other words, the well structure WE is shorter than the sourcecontact structure SCL. Furthermore, parts of the gap-fill pattern FI andthe connection part LP remain between the well structure WE and thesource line CSL.

Each of the gate stacks GST1 and GST2 is disposed between the sourcecontact structure SCL and the corresponding well structure WE that areadjacent to each other. Each gate stack GST1, GST2 encloses the pillarparts PP and is disposed on the connection part LP.

Each gate stack GST1, GST2 may include gate electrodes SSLa, SSLb, WL1to WLn, DSLa, and DSLb, and interlayer insulating layers ILD that arealternately stacked in the first direction.

Each interlayer insulating layer ILD may be formed of an insulatingmaterial such as an oxide layer. Each interlayer insulating layer ILDmay be disposed between corresponding gate electrodes SSLa, SSLb, WL1 toWLn, DSLa, and DSLb that are disposed adjacent to each other in thefirst direction.

The gate electrodes SSLa, SSLb, WL1 to WLn, DSLa, and DSLb may include asource select line SSLa or SSLb that is used as a gate electrode of asource select transistor, word lines WL1 to WLn that are used as gateelectrodes of memory cell transistors, and a drain select line DSLa orDSLb that is used as a gate electrode of a drain select transistor.

Among the gate electrodes SSLa, SSLb, WL1 to WLn, DSLa, and DSLb, thesource select line SSLa that is disposed in a lowermost layer adjacentto the source line CSL may have a stacked structure including a firstconductive layer CP1 and a second conductive layer CP2. Each of thefirst conductive layer CP1 and the second conductive layer CP2 may beformed of a conductive material selected from among various conductivematerials. For example, each of the first conductive layer CP1 and thesecond conductive layer CP2 may include at least one of a doped siliconlayer, a metal layer, a metal silicide layer, and a barrier metal layer.

In an embodiment, the first conductive layer CP1 may be formed ofconductive material capable of functioning as an etching blocking layer,and the second conductive layer CP2 may be formed of conductive materialsuitable for forming a low-resistance line. In this case, the firstconductive layer CP1 and the second conductive layer CP2 may be formedof different conductive materials. In more detail, the conductivematerial to be used for forming the first conductive layer CP1 may beselected based on an etching selectivity such that the first conductivelayer CP1 may function as an etching blocking layer during a process ofmanufacturing the semiconductor device. For example, the firstconductive layer CP1 may be formed of a doped silicon layer. The firstconductive layer CP1 may include an n-type dopant. The first conductivelayer CP1 may have a relatively large thickness so that the firstconductive layer CP1 may function as an etch stopper during themanufacturing process. As a result, the thickness of the firstconductive layer CP1 may be greater than a thickness of each of the wordlines WL1 to WLn in the first direction. The second conductive layer CP2may be formed of a conductive material having a resistance lower than aresistance of the first conductive layer CP1. For example, the secondconductive layer CP2 may be formed of a tungsten layer. Unlike thelowermost source select line SSLa, the upper source select line SSLb maybe formed of the same conductive material as the second conductive layernot including the first conductive layer CP1.

The word lines WL1 to WLn are stacked on the source select lines SSLaand SSLb and spaced apart from each other. Each of the word lines WL1 toWLn may be formed of the same conductive material as the conductivematerial of the second conductive layer CP2. Each of the word lines WL1to WLn may further include a barrier metal layer.

The drain select line DSLa or DSLb is disposed over the word lines WL1to WLn. The drain select line DSLa or DSLb may be formed of the sameconductive material as the second conductive layer CP2. The drain selectline DSLa or DSLb may further include a barrier metal layer.

The insulating spacers IS are disposed between the source contactstructure SCL and the gate stacks GST1 and GST2, and between the wellstructure WE and the gate stacks GST1 and GST2. The insulating spacersIS extend along the sidewalls of the gate stacks GST1 and GST2. The wellstructure WE and the source contact structure SCL protrude toward thesource line CSL further than the insulating spacers IS. The sourcecontact structure SCL may include a horizontal extension part EP. Thehorizontal extension part EP protrudes sideways toward the connectionpart LP of the channel pattern CH to overlap with the correspondinginsulating spacers IS. The channel pattern CH may be coupled to thehorizontal extension part EP. The channel patterns CH extending from aspace between the gap-fill insulating patterns FI and the gate stacksGST1 and GST2 into a space between the gap-fill insulating patterns FIand the source line CSL. The horizontal extension part EP is disposedbetween the gap-fill insulating pattern FI and the multilayer memorylayer ML. The horizontal extension part EP may extend to overlap thecorresponding gate stack GST1. Further, the horizontal extension part EPmay protrude from a sidewall of a lower end of the source contactstructure SCL that is adjacent to the source line CSL. The multilayermemory layer ML may protrude toward the source contact structure SCLfurther than the channel pattern CH and may be disposed on a surface ofthe horizontal extension part EP.

The connection part LP of the channel pattern CH that comes into contactwith the well structure WE may extend to the insulating spacers IS. Inother words, the connection part LP that comes into contact with thewell structure WE protrudes sideways further than the sidewall of thegate stack GST1, to overlap the lower ends of the insulating spacers IS.

The source contact structure SCL and the well structure WE may protrudetoward the upper lines BL and WPL further than the capping pattern CAPand the pillar parts PP of the channel pattern CH. Further, the sourcecontact structure SCL may protrude toward the source line CSL furtherthan the gate stacks GST so that the source contact structure SCL iscoupled to the source line CSL.

The source contact structure SCL and the well structure WE may becovered with the second upper insulating layer UIL2. The well contactplug WCT may penetrate the second upper insulating layer UIL2. The wellcontact plug WCT is coupled to the well structure WE.

The upper lines BL and WPL may include the bit lines BL and the wellpick-up line WPL, and may further include the source dummy line SDLdescribed with reference to FIG. 2B. The source dummy line SDL may becoupled to the source contact structure SCL through the dummy contactplug (DCT of FIG. 2B) passing through the second upper insulating layerUIL2.

To simplify the manufacturing process, the upper lines BL, WPL, and SDLof FIG. 2B may be disposed on the same layer. The upper lines BL, WPL,and SDL of FIG. 2B may be formed in a third upper insulating layer UIL3provided on the second upper insulating layer UIL2. The upper lines BL,WPL, and SDL of FIG. 2B may be made of a low-resistance metal.

A first conductivity type dopant may be distributed in a part of theconnection part LP that is adjacent to the source line CSL.

The upper lines BL, WPL, and SDL of FIG. 2B and the metal layers M1, M2,and M3 may be made of a low-resistance material. For example, tungstenmay be used as the low-resistance metal. Each of the barrier metallayers BM1, BM2, and BM3 may include a titanium nitride layer, atungsten nitride layer, a tantalum nitride layer or the like to preventdiffusion of the metal.

In accordance with an embodiment of the present disclosure, during aread operation or a program operation of the semiconductor device, acurrent flow path may be formed in the channel pattern CH coupledbetween the bit line BL and the source line CSL. By turning on thedischarge transistor CST, a precharge level of the bit line BL may bedischarged through the current flow path formed in the channel patternCH coupled between the bit line BL and the source line CSL.

In accordance with an embodiment of the present disclosure, during anerase operation of the semiconductor device, a current flow path may beformed in the channel pattern CH coupled between the bit line BL and thewell structure WE. During the erase operation, an erase voltage may beapplied to the well structure WE through the well pick-up line WPL. Ifthe well structure WE includes a p-type dopant, the well structure WEmay supply holes into the channel pattern CH by supplying the erasevoltage. Thereby, in an embodiment of the present disclosure, the eraseoperation may be performed reliably.

In accordance with an embodiment of the present disclosure, the sourcecontact structure SCL extends parallel to the well structure WE in thefirst direction. A source dummy line (SDL of FIG. 2B) suitable forreducing the resistance may be coupled to the source contact structureSCL extending in the first direction. Consequently, in an embodiment ofthe present disclosure, the resistance of the source line CSL may bereduced not only by the metal layer M3 of the source contact structureSCL but also by the source dummy line SDL.

FIG. 5 shows an enlarged view of region C shown in FIG. 3A, 3B or 4.

Referring to FIG. 5, the channel pattern CH may have an inner surfacefacing the capping pattern CAP and the gap-fill insulating pattern FI,and an outer surface enclosed by the multilayer memory layer ML.

The multilayer memory layer ML may include a tunnel insulating layer TIenclosing the channel pattern CH, a data storage layer DL enclosing thetunnel insulating layer TI, and a blocking insulating layer BI enclosingthe data storage layer DL. The data storage layer DL may be formed of acharge trap layer, a floating gate layer, a conductive nano dots, aphase change layer, a variable resistance layer, etc. For example, thedata storage layer may store data to be changed using Fowler-Nordheimtunneling caused by a difference in voltage between the channel patternCH and the word lines WL1 to WLn shown in FIGS. 3A to 4, and may beformed of a nitride layer capable of trapping charges. The blockinginsulating layer BI may include an oxide layer capable of blockingcharges. The tunnel insulating layer TI may be formed of a silicon oxidelayer.

The channel pattern CH may be formed of a semiconductor layer, e.g., asilicon layer. Hereinafter, a method of manufacturing a semiconductordevice in accordance with embodiments of the present disclosure will bedescribed with reference to FIGS. 6A to 8B. The following processes maybe performed after a substrate provided with a peripheral circuitincluding a discharge transistor has been provided.

FIGS. 6A to 6L show sectional views illustrating a method ofmanufacturing a semiconductor device in accordance with an embodiment ofthe present disclosure. FIGS. 6A to 6L show, by steps of the process,sectional views taken along line A-A′ of FIG. 2B.

Referring to FIG. 6A, a lower source contact plug LSCT passing throughthe lower insulating layer 101 is formed. The lower insulating layer 101may correspond to the second lower insulating layer LIL2 shown in FIGS.3A and 3B. The step of forming the lower source contact plug LSCT mayinclude the step of forming a contact hole by etching the lowerinsulating layer 101, the step of forming a barrier metal layer 103along a surface of the contact hole, and the step of forming the metallayer 105 on the barrier metal layer 103.

Thereafter, a barrier metal layer 107, a metal layer 109, and a sourcedoping semiconductor layer 111 that are provided for forming the sourceline CSL are successively stacked on the lower insulating layer 101penetrated by the lower source contact plug LSCT. Subsequently, asacrificial layer 113 is formed on the source doping semiconductor layer111. The source doping semiconductor layer 111 may include a firstconductivity type dopant. For example, the source doping semiconductorlayer 111 may be formed of an n-type doped silicon layer. Thesacrificial layer 113 may be formed of a material having an etching ratedifferent than the source doping semiconductor layer 111. In moredetail, the sacrificial layer 113 may be formed of a material whichminimizes loss of the source doping semiconductor layer 111 and isselectively etchable. For example, the sacrificial layer 113 may beformed of a titanium nitride layer (TiN).

Thereafter, the sacrificial layer 113, the source doping semiconductorlayer 111, the metal layer 109, and the barrier metal layer 107 areetched through an etching process using, as an etching barrier, a maskpattern (not shown) formed through a photolithography process. In thisway, a source line CSL that is penetrated by source holes and broughtinto contact with the lower source contact plug LSCT may be patterned.

Thereafter, the above-mentioned mask pattern (not shown) is removed, andthen supports 115 are formed so that the source holes are filled withthe respective supports 115. The step of forming the supports 115 mayinclude the step of forming an insulating layer such that the sourceholes are completely filled therewith, and the step of planarizing asurface of the insulating layer so that the sacrificial layer 113 isexposed. The insulating layer may be an oxide layer.

The metal layers 105 and 109 may be formed of a low-resistance metalsuch as tungsten to form a low-resistance line. Each of the barriermetal layers 103 and 107 may include titanium, a nitride layer, atungsten nitride layer, a tantalum nitride layer or the like to preventdiffusion of the metal.

Referring to FIG. 6B, a stack STA is formed on the sacrificial layer113. The stack STA may include a first conductive layer 127 stacked onthe sacrificial layer 113, and first material layers 131 and secondmaterial layers 133 that are alternately stacked on the first conductivelayer 127. The first material layers 131 define regions in which gateelectrodes are to be disposed, and the second material layers 133 defineregions in which interlayer insulating layers are to be disposed.

The first conductive layer 127 may be formed of material different fromthe materials of the first material layers 131 and the second materiallayers 133. In more detail, the first conductive layer 127 may be formedof material which may be used not only as a gate electrode, but also asan etch stopper during a following opening forming process. For example,the first conductive layer 127 may be formed of a doped silicon layer.In more detail, the first conductive layer 127 may be formed of a dopedsilicon layer including an n-type dopant.

The second material layers 133 may be formed of material different thanthe first material layers 131. The first material layers 131 may be madeof a sacrificial insulating material, and the second material layers 133may be made of an insulating material for interlayer insulating layers.In detail, each first material layer 131 may be formed of a siliconnitride layer, and each second material layer 133 may be formed of asilicon oxide layer.

Although not shown in the drawings, the first material layers 131 may beformed of second conductive layers for the gate electrodes SSLa, SSLb,WL1 to WLn, DSLa, and DSLb shown in FIGS. 3A and 3B, and the secondmaterial layers 133 may be formed of insulating material for interlayerinsulating layers.

Subsequently, a mask pattern 141 is formed on the stack STA. The maskpattern 141 may be patterned through a photolithography process. Themask pattern 141 may include openings that open regions in which firstholes 145 are to be defined. Thereafter, the first holes 145 throughwhich the sacrificial layer 113 is exposed may be formed by etching thestack STA through an etching process using the mask pattern 141 as anetching barrier If the sacrificial layer 113 is made of materialincluding metal such as titanium nitride TiN, the bottom of each firsthole 145 may be formed to have a relatively large width using a largedifference in etching rate between the stack STA and the sacrificiallayer 113.

Central axes of the first holes 145 may be misaligned with those of thesupports 115. For example, the first holes 145 may be disposed to notoverlap the supports 115.

Referring to FIG. 6C, the sacrificial layer 113 shown in FIG. 6B isremoved through the first holes 145. Consequently, a horizontal space147 opens in a region in which the sacrificial layer 113 has beenremoved. The horizontal space 147 meets the first holes 145, and isdefined between the source doping semiconductor layer 111 and the stackSTA.

Upper ends of the supports 115 may be exposed by the horizontal space147. The supports 115 may support the stack STA such that the gap of thehorizontal space 147 is maintained.

Referring to FIG. 6D, a multilayer memory layer 151 extending alongsurfaces of the first holes 145, a surface of the horizontal space 147,and side surfaces of the supports 115 is formed. The step of forming themultilayer memory layer 151 may include the step of forming a blockinginsulating layer, the step of forming a data storage layer on theblocking insulating layer, and the step of forming a tunnel insulatinglayer on the data storage layer. The structure and material of each ofthe blocking insulating layer, the data storage layer, and the tunnelinsulating layer are the same as those described with reference to FIG.5.

Thereafter, a channel layer 153 is formed on a surface of the multilayermemory layer 151. The channel layer 153 may extend along the surfaces ofthe first holes 145, the surface of the horizontal space 147, and theside surfaces of the supports 115 and be enclosed by the multilayermemory layer 151.

The channel layer 153 may be formed of a semiconductor layer. Forinstance, the channel layer 153 may be formed by depositing a siliconlayer. The channel layer 153 may be formed of an integrated layerwithout having an interface. The channel layer 153 may include theconnection part LP and the pillar parts PP extending from the connectionpart LP in the first direction. The connection part LP is disposed onthe source line CSL and extends along both the surface of the horizontalspace 147 between the source line CSL and the stack STA and along thesurfaces of the supports 115. The pillar parts PP are enclosed by thestack STA.

A central region of each first hole 145 defined by the channel layer 153and a central region of the horizontal space 147 are filled with agap-fill insulating layer 155. The gap-fill insulating layer 155 isenclosed by the channel layer 153. The step of forming the gap-fillinsulating layer 155 may include the step of filling the first holes 145and the horizontal space 147 with a material layer having fluidity, andthe step of hardening the material layer having the fluidity.Polysilazane (PSZ) may be used as the material layer having fluidity.

The step of forming the gap-fill insulating layer 155 may furtherinclude the step of recessing a portion of the gap-fill insulating layer155 so that the height of the gap-fill insulating layer 155 is less thana height of the channel layer 153. Thereby, the gap-fill insulatinglayer 155 is enclosed by the channel layer 153, and has a height lessthan a height of the channel layer 153. A central region of the channellayer 153 that is exposed on the gap-fill insulating layer 155 may befilled with the capping pattern 157. The capping pattern 157 may beformed of a doped silicon layer including a first conductivity typedopant.

Subsequently, although not shown, a stepwise structure may be formed bypatterning the stack STA. Thereafter, the mask pattern is removed.

Thereafter, a first upper insulating layer 161 is formed on the stackSTA to cover the capping pattern 157 and the stepwise structure. Asurface of the first upper insulating layer 161 may be planarized.

Referring to FIG. 6E, first trenches 165 are formed by etching the upperinsulating layer 161 and the stack STA described with reference to FIG.6D through an etching process that stops when the first conductive layer127 is exposed. The first conductive layer 127 is made of a materialhaving an etch rate different than the first material layers 131 and thesecond material layers 133 of the stack STA shown in FIG. 6D. As aresult, the depth of each of the first trenches 165 may be easilycontrolled such that the first trenches 165 pass through the firstmaterial layers 131 and the second material layers 133 without passingthrough the first conductive layer 127. To form the first trenches 165,a mask pattern (not shown) that opens a region in which the firsttrenches 165 are to be formed may be formed on the upper insulatinglayer 161. The mask pattern may be removed after the first trenches 165have been formed. The first trenches 165 are formed to define spaces forarrangement of the source contact structure SCL and the well structureWE. In a plan view, the first trenches 165 may extend parallel to eachother in the second direction.

If the first material layers 131 are formed of sacrificial insulatingmaterial, the first material layers 131 may be replaced with secondconductive layers 171 through the first trenches 165. The step ofreplacing the first material layers 131 with the second conductivelayers 171 may include a step of removing the first material layer 131through the first trenches 165 and opening gate areas, the step offilling the gate areas with a third material layer, and the step ofremoving the third material layer from the first trenches 165 such thatthe third material layer is divided into the second conductive layers171. The third material layer may be a conductive material forming thesecond conductive layers 171 and may be a metal layer having resistancelower than a resistance of the first conductive layer 127. Before thethird material layer is formed, an aluminum oxide layer (not shown) maybe further formed along surfaces of the gate areas. The aluminum oxidelayer functions as a blocking insulating layer.

Unlike described above, if the first material layers 131 are made of aconductive material, the first material layers 131 may remain separatedinto a plurality of gate electrodes by the first trenches 165 withoutbeing replaced with the second conductive layers 171.

Referring to FIG. 6F, to extend the first trenches 165 to a depth suchthat the first conductive layer 127 is penetrated, the first conductivelayer 127 may be etched using an etch-back process. Thereby, the gatestacks GST described with reference to FIGS. 3A to 3B may be patterned.Hereinbelow, the first trenches 165 having an extended length will bedefined in a first opening 173A and a second opening 173B. The stack isdivided into gate stacks GST by the first opening 173A and the secondopening 173B. Each of the gate stacks GST is disposed between thecorresponding first and second openings 173A and 173B that are adjacentto each other. The first opening 173A and the second opening 173B areformed to define spaces for arrangement of the source contact structureSCL and the well structure WE that are shown in FIG. 2A. In a plan view,the first opening 173A and the second opening 173B may extend parallelto each other in the second direction.

Thereafter, insulating spacers 175 may be formed on sidewalls of thefirst and second openings 173A and 173B. The step of forming theinsulating spacer 175 may include the step of depositing an insulatinglayer along the surfaces of the first and second openings 173A and 173B,and the step of etching the insulating layer through an etch-backprocess. During the step of etching the insulating layer, the multilayermemory layer 151 may be exposed through the bottom of each of the firstand second openings 173A and 173B.

Thereafter, the connection part LP of the channel layer 153 is exposedby etching the multilayer memory layer 151, which is exposed through thebottom of each of the first and second openings 173A and 173B.Subsequently, the gap-fill insulating layer 155 may be exposed byetching the connection part LP of the exposed channel layer 153.Thereby, each of the first and second openings 173A and 173B may extendto pass through the multilayer memory layer 151 and the connection partLP of the channel layer 153 to expose the gap-fill insulating layer 155.The first opening 173A and the second opening 173B may extend toward thesource line CSL further than the insulating spacers 175. Each of thefirst and second openings 173A and 173B may be formed to a depth towhich an upper surface of the connection part LP of the channel 153 isexposed.

Referring to FIG. 6G, a well doping layer 181 is formed along the firstopening 173A and the second opening 173B. In more detail, the welldoping layer 181 is formed on the surfaces of the insulating spacers175, the side surface of the multilayer memory layer 151 that is exposedthrough the first and second openings 173A and 173B, the sidewall of theconnection part LP, and the surface of the gap-fill insulating layer155. The well doping layer 181 comes into contact with the channel layer153.

The well doping layer 181 is formed of a semiconductor layer includingat a first concentration a second conductivity type dopant differentfrom the first conductivity type dopant. The second conductivity typedopant may be a p-type dopant capable of supplying holes to the channellayer 153. For example, the well doping layer 181 may be formed of ap-type doped silicon layer.

The well doping layer 181 may have a thickness at which a lower portionof each of the first and second openings 173A and 173B may be completelyfilled with the well doping layer 181. The thickness of the well dopinglayer 181 may be modified in various ways, and one of the modificationswill be described later herein with reference to FIG. 8A.

Referring to FIG. 6H, a mask pattern 183 is formed on the well dopinglayer 181. The mask pattern 183 blocks the first opening 173A and opensthe second opening 173B. The well doping layer 181 is removed from thesecond opening 173B through an etching process using the mask pattern183 as an etching barrier. Thereby, the second opening 173B and theinsulating spacers 175 disposed in the second opening 173B are exposed.

Thereafter, a source trench ST through which the source line CSL isexposed may be formed by etching, through the second opening 173B, thegap-fill insulating layer 155 under the second opening 173B, themultilayer memory layer 151, and the connection part LP of the channellayer 153. The source doping semiconductor layer 111 of the source lineCSL may be exposed to a depth that the source trench ST attains.

An additional first conductivity dopant may be doped in the sourcedoping semiconductor layer 111 exposed through the source trench ST.

During a process of forming the source trench ST, the connection part LPof the channel layer 153 may be etched in a direction parallel to thesource line CSL, whereby a recess area RA may be defined. The recessarea RA may extend in a horizontal direction from a side portion of thesource trench ST and overlap with lower ends of the insulating spacers175.

Referring to FIG. 61, the well doping layer 181 that remains in thefirst opening 173A is exposed by removing the mask pattern 183 describedwith reference to FIG. 6H. Subsequently, a source contact layer 185 isformed on the well doping layer 181 so that the source trench ST and thesecond opening 173B are filled with the source contact layer 185. Thesource contact layer 185 may be formed of an undoped semiconductorlayer. For example, the source contact layer 185 may be formed of anundoped silicon layer. If the recess area RA has been formed, the recessarea RA is filled with the source contact layer 185.

The source contact layer 185 may electrically couple the connection partLP of the channel layer 153 with the source line CSL. The firstconductivity type dopant may be diffused from the source dopingsemiconductor layer 111 into both a lower portion of the source contactlayer 185 that is adjacent to the source doping semiconductor layer 111and into the connection part LP coupled to the source contact layer 185.Here, a height of diffusion of the first conductivity type dopant may becontrolled so that the first conductivity type dopant is prevented frombeing diffused into an upper portion of the source contact layer 185.

Referring to FIG. 6J, the well doping layer 181 and the source contactlayer 185 are etched so that the well doping layer 181 and the sourcecontact layer 185 that are shown in FIG. 6I remain at a height less thana height of the upper surface of the gate stack GST. Thereby, an upperend of each of the first and second openings 173A and 173B is exposed.The well doping layer 181 remains as a first well pattern 181W in onlythe first opening 173A. The source contact layer 185 remains as thefirst source contact pattern 185S in only the second opening 173B. Inaddition, an upper surface of the first upper insulating layer 161 isexposed.

Referring to FIG. 6K, a second conductivity type dopant is implanted ata second concentration higher than the first concentration into upperends of the first well pattern 181W and the first source contact pattern185S that remain exposed through the first opening 173A and the secondopening 173B. Thereby, an ohmic contact area 181OC is defined on theupper end of the first well pattern 181W, and a dummy contact area 185DCis defined on the upper end of the first source contact pattern 185S.

Referring to FIG. 6L, the upper end of each of the first and secondopenings 173A and 173B may be completely filled with a barrier metallayer 191 and a metal layer 193. The metal layer 193 may be provided toform a low-resistance line and may be formed of low-resistanceconductive material such as tungsten. The barrier metal layer 191 mayinclude a titanium nitride layer, a tungsten nitride layer, a tantalumnitride layer, or the like to prevent diffusion of metal.

The source contact structure SCL and the well structure WE that areshown in FIG. 3A may be formed through the above-mentioned process.

Thereafter, a second upper insulating layer 195 may be formed on thefirst upper insulating layer 161 to cover the barrier metal layer 191and the metal layer 193. Subsequently, contact plugs BCT and WCT passingthrough at least one of the first upper insulating layer 161 and thesecond upper insulating layer 195 may be formed. Here, the dummy contactplug DCT shown in FIG. 2B may be further formed. The bit line contactplug BCT may be brought into contact with the capping pattern 157 andmay be electrically coupled to the pillar parts PP of the channel layer153. The well contact plug WCT may come into contact with the metallayer 193 in the first opening 173A. Although not shown, if the dummycontact plug DCT is formed, the dummy contact plug DCT may come intocontact with the metal layer 193 in the second opening 173B.

Thereafter, a third upper insulating layer 197 may be formed on thesecond upper insulating layer 195 to cover the contact plugs BCT andWCT. The upper lines BL and WPL are thereafter formed and coupled to thecontact plugs BCT and WCT through the third upper insulating layer 197.Including the bit line BL and the well pick-up line WPL, the upper linesBL and WPL may further include the source dummy line SDL shown in FIG.2B. At least one of the well pick-up line WPL and the source dummy lineSDL may be formed simultaneously with the bit line BL.

The bit line BL may be coupled to the pillar parts PP of the channellayer 153 via the bit line contact plug BCT and the capping pattern 157.The well pick-up line WPL may be coupled to the metal layer 193 in thefirst opening 173A via the well contact plug WCT. The metal layer 193 inthe second opening 173B may be coupled to the source dummy line SDLshown in FIG. 2B via the dummy contact plug DCT shown in FIG. 2B.

FIG. 7 shows a sectional view illustrating a method of manufacturing asemiconductor device in accordance with an embodiment of the presentdisclosure. Particularly, FIG. 7 is a sectional view illustrating amodification of a process of forming a hole passing through the stack.

Referring to FIG. 7, a source line CSL and a sacrificial layer 113 thatare penetrated by supports 115 are formed through processes describedwith reference to FIG. 6A. Thereafter, the stack STA and the maskpattern 141 described with reference to FIG. 6B are formed.Subsequently, as described with reference to FIG. 6B, the step offorming the mask pattern 141 and the step of forming the first holes 145are performed. The width of a lower end of each of the first holes 145may be thereafter widened by selectively etching the first conductivelayer 127 having an etching rate different than an etching rate of thefirst and second material layers 131 and 133 through side surfaces ofthe first holes 145. If the widened portion is defined as a second hole145B, a second width W2 of the second hole 145B is greater than a firstwidth W1 of the first hole 145. Thereby, during a following process, adeposition margin of the multilayer memory layer and the channel layermay be secured.

After the second hole 145B has been formed, the processes described withreference to FIGS. 6C to 6L may be performed.

FIGS. 8A and 8B show sectional views illustrating a method ofmanufacturing a semiconductor device in accordance with an embodiment ofthe present disclosure. Particularly, FIGS. 8A and 8B show sectionalviews illustrating a modification of the process of forming the welldoping layer.

Referring to FIG. 8A, a lower insulating layer 201, a lower sourcecontact plug LSCT, a source line CSL, a support 215, a multilayer memorylayer 251, a channel layer 253, a gap-fill insulating layer 255, acapping pattern 257, a first upper insulating layer 261, gate stacksGST, a first opening 273A, a second opening 273B, and insulating spacers275 are formed through the processes described with reference to FIGS.6A to 6F.

The first opening 273A and the second opening 273B separate the gatestacks GST from each other and extend toward the source line CSL furtherthan the insulating spacers 275 so that the connection part LP of thechannel layer 253 is exposed.

Thereafter, a well doping layer 281 is formed along the first opening273A and the second opening 273B. The well doping layer 281 comes intocontact with the channel layer 253. A central region of each of thefirst and second openings 273A and 273B may be left open by the welldoping layer 281.

The well doping layer 281 may be formed of the same material layer asthe well doping layer 181 described with reference to FIG. 6G.

Referring to FIG. 8B, the same processes as described with reference toFIGS. 6H to 6 j are performed. Thereby, a first well pattern 281W and afirst source contact pattern 285S are defined. In accordance with anembodiment of the present disclosure, the first well pattern 281W may bepatterned to have a U-shaped cross-sectional structure. Consequently, anundoped layer 285UDP may remain in the first opening 273A during theprocess of forming the first source contact pattern 285S. The undopedlayer 285UDP may be made of the same material as that of a sourcecontact layer that forms the first source contact pattern 285S, andremain enclosed by the first well pattern 281W in the first opening273A.

Thereafter, an ohmic contact area OC and a dummy contact area DC may beformed by performing the same process as that described with referenceto FIG. 6K. The ohmic contact area OC is defined in upper ends of thefirst well pattern 281W and the undoped layer 285UDP. The dummy contactarea DC is defined in an upper end of the first source contact pattern285S.

Thereafter, as described with reference to FIG. 6L, an upper end of eachof the first and second openings 273A and 273B is completely filled withthe barrier metal layer 291 and the metal layer 293. Thereby, the sourcecontact structure SCL and the well structure WE described with referenceto FIG. 4 may be formed.

Thereafter, in the same manner as that described with reference to FIG.6L, a following process of forming the contact plugs BCT and WCT and theupper lines BL and WPL may be performed.

FIG. 9 shows a block diagram illustrating a configuration of a memorysystem 1100 in accordance with an embodiment of the present disclosure.

Referring FIG. 9, the memory system 1100 in accordance with anembodiment includes a memory device 1120 and a memory controller 1110.

As described with reference to FIGS. 3A to 4, the memory device 1120 mayinclude a well structure and a source contact structure that are formedto different depths in opposite sides of a gate stack and coupled to achannel pattern. The well structure is spaced apart from a source linedisposed below the gate stack, and the source contact structure extendsto a depth greater than a depth of the well structure so that the sourcecontact structure comes into contact with the source line.

The memory controller 1110 may be configured to control the memorydevice 1120, and include a static random access memory (SRAM) 1111, aCPU 1112, a host interface 1113, an error correction code (ECC) 1114,and a memory interface 1115. The SRAM 1111 may be used as an operatingmemory of the CPU 1112. The CPU 1112 may perform overall controloperations for data exchange of the memory controller 1110. The hostinterface 1113 may be provided with a data interchange protocol of ahost coupled with the memory system 1100. Furthermore, the ECC 1114 maydetect and correct an error included in the data that is read from thememory device 1120, and the memory interface 1115 may interface with thememory device 1120. In addition, the memory controller 1110 may furtherinclude a read only memory (ROM) or the like that stores code data forinterfacing with the host.

The above-described memory system 1100 may be a memory card or a solidstate disk (SSD) equipped with the memory device 1120 and the controller1110. For example, when the memory system 1100 is an SSD, the memorycontroller 1110 may communicate with an external device (e.g., a host)via one of various interface protocols, such as a universal serial bus(USB), a multimedia card (MMC), a peripheral componentinterconnection-express (PCI-E), a serial advanced technology attachment(SATA), a parallel advanced technology attachment (PATA), a smallcomputer small interface (SCSI), an enhanced small disk interface(ESDI), and an integrated drive electronics (IDE).

FIG. 10 shows a block diagram illustrating a configuration of acomputing system 1200 in accordance with an embodiment of the presentdisclosure.

Referring to FIG. 10, the computing system 1200 in accordance with anembodiment of the present disclosure may include a CPU 1220, a randomaccess memory (RAM) 1230, a user interface 1240, a modem 1250, and amemory system 1210 that are electrically coupled to a system bus 1260.Furthermore, if the computing system 1200 is a mobile device, it mayfurther include a battery for supplying operating voltage to thecomputing system 1200. An application chip set, a camera image processorCIS, a mobile DRAM and the like may be further included.

As described above with reference to FIG. 9, the memory system 1210 maybe configured with a memory device 1212 and a memory controller 1211.

In accordance with embodiments of the present disclosure, a channelpattern may include a first terminal coupled to a well structure, and asecond terminal coupled to a source line. Thereby, embodiments of thepresent disclosure may separately perform an operation of controllingthe flow of current in a channel pattern through the source line, and anoperation of supplying, through the well structure, holes for an eraseoperation. Hence, the operational reliability of the semiconductordevice may be improved.

In accordance with embodiments of the present disclosure, openings maybe used to couple the well structure and the source line to differentterminals of the channel pattern. Therefore, a process of manufacturingthe semiconductor device may be simplified.

Examples of embodiments have been disclosed herein, and althoughspecific terms are employed, the terms are used and are to beinterpreted in a generic and descriptive sense only and not for purposeof limitation. In some instances, as would be apparent to one ofordinary skill in the art as of the filing of the present application,features, characteristics, and/or elements described in connection witha particular embodiment may be used singly or in combination withfeatures, characteristics, and/or elements described in connection withother embodiments unless otherwise specifically indicated. Accordingly,it will be understood by those of skill in the art that various changesin form and details may be made without departing from the spirit andscope of the present disclosure as set forth in the following claims.

What is claimed is:
 1. A semiconductor device comprising: a source lineformed over a substrate; a channel pattern including a connection partdisposed over the source line, and pillar parts protruding from theconnection part in a first direction; a well structure protruding fromthe connection part in the first direction and spaced apart from thesource line; a source contact structure protruding from the source linein the first direction and passing through the connection part; and agate stack disposed between the source contact structure and the wellstructure and enclosing the pillar parts over the connection part. 2.The semiconductor device according to claim 1, wherein the wellstructure and the source contact structure extend in a second directionintersecting with the first direction.
 3. The semiconductor deviceaccording to claim 1, further comprising insulating spacers disposedbetween the gate stack and the well structure and between the gate stackand the source contact structure, wherein the well structure and thesource contact structure protrude toward the source line further thanthe insulating spacers.
 4. The semiconductor device according to claim3, wherein the source contact structure comprises a horizontal extensionpart protruding sideways toward the connection part of the channelpattern and overlapping the corresponding insulating spacer.
 5. Thesemiconductor device according to claim 1, wherein: the source lineincludes a first conductivity type dopant; and at least a portion of thewell structure that comes into contact with the connection part of thechannel pattern includes a second conductivity type dopant differentfrom the first conductivity type dopant.
 6. The semiconductor deviceaccording to claim 5, wherein: the first conductivity type dopant is ann-type dopant; and the second conductivity type dopant is a p-typedopant.
 7. The semiconductor device according to claim 1, wherein: thesource contact structure comprises: a source contact layer extendingfrom the source line in the first direction and formed lower than thegate stack; and a metal layer coupled to the source contact layer; thesource contact layer includes an undoped area and a dummy contact area;the dummy contact area is defined as an area in which a secondconductivity type dopant is distributed in an upper end of the sourcecontact layer; and the metal layer comes into contact with the dummycontact area and extends in the first direction.
 8. The semiconductordevice according to claim 7, wherein: the source contact layer includesa lower end coming into contact with the source line and the connectionpart of the channel pattern; a first conductivity type dopant isdistributed in the source line and the lower end of the source contactlayer; and the undoped area remains between the lower end of the sourcecontact layer and the dummy contact area.
 9. The semiconductor deviceaccording to claim 1, wherein the well structure comprises: a welldoping layer coming into contact with the connection part of the channelpattern and extending in the first direction, the well doping layerbeing formed lower than the gate stack and including a secondconductivity type dopant at a first concentration; an ohmic contact areadefined in an upper end of the well doping layer and including thesecond conductivity type dopant at a second concentration higher thanthe first concentration; and a metal layer coming into contact with theohmic contact area and extending in the first direction.
 10. Thesemiconductor device according to claim 9, wherein the well structurefurther comprises an undoped semiconductor layer enclosed by the welldoping layer.
 11. The semiconductor device according to claim 1, furthercomprising a discharge transistor disposed between the substrate and thesource line and coupled to the source line to determine whether todischarge a voltage of the source line.
 12. The semiconductor deviceaccording to claim 1, further comprising: bit lines coupled to thepillar parts of the channel pattern; and a well pick-up line coupled tothe well structure to supply a well voltage to the well structure. 13.The semiconductor device according to claim 12, wherein the well pick-upline and the bit lines are disposed on the same layer.
 14. Thesemiconductor device according to claim 12, further comprising a sourcedummy line disposed on the same layer as the well pick-up line andcoupled to the source contact structure, the source dummy line beingformed of a metal layer.
 15. A semiconductor device comprising: gatestacks disposed over a source line; a source contact structure disposedbetween the gate stacks and protruding toward the source line furtherthan the gate stacks so that the source contact structure is coupled tothe source line; insulating spacers disposed between the gate stacks andthe source contact structure; and horizontal extension parts protrudingfrom a sidewall of a lower end of the source contact structure that isadjacent to the source line and overlapping the insulating spacers. 16.The semiconductor device according to claim 15, further comprisinggap-fill insulating patterns filling a space between the gate stacks andthe source line, and extending to pass through the gate stacks, thegap-fill insulating patterns being separated from each other with thesource contact structure interposed between the gap-fill insulatingpatterns; channel patterns extending from a space between the gap-fillinsulating patterns and the gate stacks into a space between thegap-fill insulating patterns and the source line, the channel patternsbeing coupled to the horizontal extension parts; and multilayer memorylayers extending from a space between the channel patterns and the gatestacks into a space between the channel patterns and the source line.17. The semiconductor device according to claim 16, wherein themultilayer memory layers protrude toward the source contact structurefurther than the channel patterns, and extend onto the horizontalextension parts.
 18. The semiconductor device according to claim 15,wherein the horizontal extension parts extend to overlap the gatestacks.
 19. The semiconductor device according to claim 15, furthercomprising a well structure facing the source contact structure witheach of the gate stacks interposed between the well structure and thesource contact structure, the well structure being shorter than thesource contact structure so that the well structure is spaced apart fromthe source line.
 20. The semiconductor device according to claim 19,wherein the source line and the well structure respectively includedopants of different conductivity types.